Constraints on the small scale curvature perturbation using Planck-2015 data

Understand

The particles emitted from PBHs through the Hawking radiation have interactions with the particles present in the Universe.

• Due to the interactions, the evolution of the intergalactic medium (IGM) is changed and the changes have imprints on the anisotropies of the cosmic microwave background (CMB).
• In this paper, we focus on the PBHs with the lifetime in the range of $10^{13}s \lesssim \tau_{\rm PBH} \lesssim 10^{17}s$, corresponding to the mass range of $2.8\times 10^{13}\mathrm{g} \lesssim M_{\mathrm{PBH}} \lesssim 2.5\times 10^{14}\mathrm{g}$.
• We update the constraints on the initial mass fraction of PBHs using the Plank-2015 data.